Radial piston pump

ABSTRACT

A radial piston pump or motor including an elongated rotary cylinder block having axially and angularly spaced fluid cylinders extending through the axis of rotation, with axial porting provided to opposite ends of the cylinder block for flow to and from the cylinders through stationary valve plates communicating with a common inlet manifold and a common outlet manifold. The cylinders have reciprocable pistons with universal bearing slippers engaging separate cam tracks in a surrounding cam ring. Each cam track as a spherical cam surface with a center on the center line of the cam ring and offset from the axis of the associated piston, and the bearing slipper has a mating surface. Displacement is variable by application of fluid under pressure to opposite sides of the ring.

United States Patent [191 Carlson [11] 3,788,779 Jan. 29, 1974 RADIAL PISTON PUMP [76] Inventor: Floyd E. Carlson, 4504 Lanewood Cir., Rockford, Ill. 61 108 [22] Filed: May 27, 1971 21 Appl. No.: 147,443

[56] References Cited UNITED STATES PATENTS 2,433,484 12/1947 Roth 418/26 3,181,475 5/1965 Thompson 91/502 3,663,125 5/1972 Freeman 91/478 3,650,180 3/1972 Gantschnigg 91/488 3,081,708 3/1963 Nyman et a1. 91/492 3,518,919 7/1970 Freeman... 91/491 3,084,633 4/1963 l-lenrichsen 91/488 3,028,814 4/1962 Rumsey et a1 417/219 3,122,971 3/1964 Russell 91/491 FOREIGN PATENTS OR APPLICATIONS 41 1,299 7/1945 ltaly 417/462 537,240 2/1922 France 417/462 Primary Examiner-William L. Freeh Assistant Examiner-Gregory LaPointe Attorney, Agent, or Firm-Hofgren, Wegner, Allen, Stellman and McCord [5 7] ABSTRACT A radial piston pump or motor including an elongated rotary cylinder block having axially and angularly spaced fluid cylinders extending through the axis of rotation, with axial porting provided to opposite ends of the cylinder block for flow to and from the cylin ders through stationary valve plates communicating with a common inlet manifold and a common outlet manifold. The cylinders have reciprocable pistons with universal bearing slippers engaging separate cam tracks in a surrounding cam n'ng. Each cam track has a spherical cam surface with a center on the center line of the cam ring and ofiset from the axis of the associated piston, and the bearing slipper has a mating sur- -face. Displacement is variable by application of fluid under pressure to opposite sides of the ring.

15 Claims, 5 Drawing Figures PAIENTEBJANZSIQH sum 1 v or 2 FIGI FlGld INVENTORQ FLOYD E. CARLSON W, I/figwn ATTORNEYS.

RADIAL PISTON PUMP BACKGROUND OF THE INVENTION In the past, rotary radial piston hydraulic units have been known and for the most part they have involved a construction in which a plurality of radial cylinders are provided in a cylinder block in a single plane transverse to the axis of rotation of the cylinder block for receiving reciprocable pistons adapted to be stroked by a surrounding cam ring. In other constructions, it has also been known to provide more than one annular series of cylinders and to locate a second series in a transverse plane axially spaced from the first series. Generally such devices have the limitation that the diameter of the cylinder block is relatively large in comparison to the stroke of the pistons for the reason that the cylinders cannot extend all the way to the center line of the cylinder block, or across such center line, without intersecting other cylinders. At any given speed in rpm, the surface speed of the bearing slippers relative to the cam track and the surface speed of the cylinder block relative to the valve plate is increased with increase in cylinder block diameter, so that enlarged cylinder blocks impose limitations on the maximum rpm that the block can be rotated.

It is possible to reduce the' cylinder block diameter, increase the piston stroke, and increase the torque producing angle in radial piston units by extending the cylinder length through the axis of cylinder block rotation. Little has been found in the prior art concerning such construction. In this regard, U.S. Pat. No. 3,374,750 shows a single piston pump with the cylinder extending through the axis of rotation, and general-reference is made to the possibility of plural pistons, but there is no illustration of the latter.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved radial piston pump or motor construction including a rotary cylinder block with radial cylinders extending through the axis of cylinder block rotation in a manner to provide relatively great piston stroking with relatively small overall diameter, in an arrangement utilizing a plurality of cylinders which are axially and angularly spaced in the cylinder block and ported from the bottom of each cylinder axially to the end of the cylinder block.

In a preferred construction, each cylinder is ported axially to opposite ends of the cylinder block to stationary valve plates which each have an arcuate inlet port communicating with a common inlet manifold and an arcuate outlet port communicating with a common outlet manifold.

The axially spaced pistons are movable radially outwardly by centrifugal force on rotation of the cylinder block and are moved radially inwardly by a surrounding cam ring which includes a separate cam track for each piston. Each cam track includes a cam surface which is spherical about a center which falls on the axis of the cam ring but offset from the axis of the associated piston. Each piston has a bearing slipper with a mating surface in contact with the cam surface. The mating surface facilitates formation of a pressure balance chamber in the surface of the slipper. The offset center of the cam surface relative to thepiston axis results in canting the slipper relative to the axis of the piston to produce rotary motion of the piston on rotation of the cylinder block.

The cam ring is biased toward a central position concentric with the cylinder block by resilient retainer means acting at diametrically opposite positions on the periphery of the ring. In order to vary the position of the ring eccentrically in opposite directions from neutral, the ring is mounted in a fluid-tight chamber, and fluid under pressure may be applied selectively to one side or the other to move the ring against the centering force of the resilient retaining means.

In the preferred construction illustrated, the cam ring has opposite ends in sealing engagement with the ring chamber. At the periphery of the ring, sealing rods act between the ring and the side walls of the ring chamber so as to provide separate fluid pressure chambers for moving the ring into stroke in opposite directions. In each pressure chamber, the sealing rods are retained in position by an arched leaf spring in turn engaged by a spring-biased plunger in the housing. The spring means acts to retain the sealing rods in position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view through a radial piston pump or motor incorporating the principles of the present invention;

FIG. 1a is a fragmentary enlarged sectional view like FIG. 1, showing the relationship of piston and cam track.

FIG. 2 is a transverse cross section taken at about the line 2'2 of FIG. 1

FIG. 3 is a longitudinal sectional view taken at about the line 3-3 of FIG. 1, with some parts omitted; and

FIG. 4 is a cross section taken at about the line 4--4 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail, the device includes a housing comprised of a central hollow member and end closure members 11 and 12 suitably secured together as by bolts or screws 15. The housing is somewhat rectangular in cross section, and as seen best in FIGS. 1 and 2, it defines a chamber 16 for housing a rotary cylinder block 17 and a generally cylindrical cam ring 18 surrounding the cylinder block. The chamber 16 includes end walls 20 and 21, side walls 22 and 23, and top and bottom walls 25 and 26.

The cylinder block 17 includes a generally cylindrical main body with a plurality of radially disposed fluid cylinders as at 28, each of which contains a reciprocable piston 29 slidable in a suitable liner 30 in the cylinder. The fluid chambers 28 are radially disposed and each extends from the periphery of the cylinder block radially inwardly past the axis of rotation of the cylinder block, nearly to the diametrically opposite periphery of the cylinder block. The cylinders are axially spaced as seen in FIG. 1 and they are angularly spaced relative to each other as seen in FIG. 2. In the construction illustrated, five pistons are utilized at about72 apart so as to be equally spaced about the periphery of the cylinder block.

In order to port fluid to and from the fluid chambers 28, the cylinder block includes a plurality of axially disposed passages or ports 35, each of which intersects one of the fluid chambers 28. Each of the axial passages extends the entire length of the main body of the cylinder block to opposite end faces thereof for communication with appropriate valving. As illustrated, a valve plate 37 is provided at each end of the cylinder block, and each valve plate includes a pair of symmetrically disposed arcuately shaped inlet and outlet ports 38 and 39 (FIG. 4) adapted for successive communication with axial passages 35 as the cylinder block rotates.

In operation, as thus far described, it will be understood that if the device is utilized as a pump, rotating in a clockwise direction as viewed in FIGS. 2 and 4, arcuate port 39 will function as an inlet port admitting fluid to successive axial passages 35 as the pistons move outwardly relative to the cylinder block on intake strokes as a result of the action of centrifugal force, whereas the arcuate port 38 will function as an outlet port from which fluid under pressure is delivered as the axial passages 35 successively communicate with port The cylinder block is formed with reduced axial shaft extensions at opposite ends as at 41 and 42 which are appropriately mounted in suitable bearings such as bushings 44 in the end cover members 11 and 12. Preferably a suitable rotary seal 46 is provided in the cover member 12 to prevent leakage of fluid outside the housing. A similar seal may be provided at 47 on shaft 41 in cover member 11. One of the shaft extensions, such as 42, is appropriately formed with a splined terminal portion as at 48 for connection with a driving member when the unit-is utilized as a pump and for connection with a driven member when the unit is utilized as a motor.

As seen in FIG. 4, the arcuate inlet port 39 in valve plate 37 communicates with three arcuately arranged ports 50 leading to an inlet manifold 52 (FIG. 3) in the end cover member 11. At the opposite end of the pump structure, the corresponding valve inlet port 39 communicates with a similar array of ports 50 in the cover member 12 leading to the opposite end of inlet manifold 52 which also extends through the central housing member 10, so that both ends of the cylinder block communicate with a common inlet. The housing member includes an inlet port 54 communicating with the inlet manifold 52 for supplying fluid to the housing.

Referring again to FIG. 4, the arcuate outlet port 38 in valve plate 37 communicates with three arcuately arranged outlet ports 55 leading to an outlet manifold 56 in the end cover member 11. In similar fashion, at the opposite end of the pump, the arcuate outlet port 38 communicates with three arcuately arranged ports 55 leading to outlet manifold 56 in cover member 12. The manifold passage 56 continues through the central housing member 10, and the latter includes an outlet port 58 communicating with manifold 56.

In order to maintain the valve plates 37 in sealing engagement with the adjacent end of the cylinder block, each of ports 50 and 55 is formed with a counterbore for receiving a transfer bushing or piston as at 61) which engages the valve plate and transfer fluid pressure tending to maintain the plate in fluid tight sealing engagement with the end of the cylinder block. The bushing is backed by a sealing ring 61 of Teflon which provides peripheral sealing. The sealing ring 61 bears against a backup washer 62 seated on a spring washer as at 63, which tends to maintain the valve plate against the cylinder block until pressure is developed to act through pistons 60.

For purposes of controlling reciprocation of the pistons, the cam ring 18 is formed with a plurality of axially adjacent cam tracks as at 65 of similar configuration, each adapted for cooperation with a complementary bearing slipper 67 on the end of each piston. As illustrated, each piston is formed with a spherical end 68 and each bearing slipper 67 is formed with a shank portion 69 crimped on the spherical end 68 for purposes of mounting the bearing Slipper on the piston for universal movement relative thereto.

In order to provide for rotation of the bearing slipper and piston about the longitudinal axis of the piston as the cylinder block rotates, each of the cam tracks 65 is formed with a spherically shaped cam surface concentric about a center as at 70 (FIG. 1a) which falls on the axis A of the cam ring and which is displaced from the center line C of the associated piston. Additionally, the bearing slipper is formed with a complementary spherical outer bearing surface of similar radius adapted to engage the surface of the cam track. The arrangement of the center 70 of the surface of the cam track offset from the center line C of the piston results in a tipping of the bearing shoe in a manner such that the slipper has a greater surface in contact with the cam surface at one side of the path of motion represented by the center line of the piston. The greater frictional drag at one side of the slipper with the greater surface in contact with the cam produces a rotating motion of the slipper which in turn produces a rotating motion of the piston as the cylinder block rotates.

In order to pressure balance the slipper and reduce the friction and wear at the contact with the cam track,

the surface of the slipper in contact with the cam is provided with a recess 72 which functions as a pressure balance chamber at the interengagement of the bearing slipper and the cam track. Fluid under pressure is supplied to the pressure balance chamber 72 through a passage 73 extending throughout the length of the piston so that fluid under pressure from the fluid chamber 28 is supplied to the pressure balance chamber 72. The degree of pressure balance is determined by the area of the chamber 72, and preferably there is a counterbalance on the order of 97 per cent.

The cam ring 18 is normally urged to acentral position in the chamber 16 where the ring is concentric with the cylinder block 17. so that there will be no reciprocation of the pistons on rotation of the cylinder block and therefore no-displacement of fluid. The cam ring 18 is movable in opposite radial directions from the neutral concentric position by supply of fluid under pressure to either the top of the chamber 16 or the bottom of the chamber 16. In order to provide separate sealed chambers at the top of the cam ring and the bottom of the cam ring in the'chamber l6, opposite ends of the ring have sealing engagement with opposite end walls 20 and 21 of the chamber 16 which are the inner faces of the end cover members 1 1 and 12'. As seen best in FIG. 2, diametrically opposite peripheral sides of the cam ring 18 fit closely adjacent opposite side walls 22 and 23 of the chamber 16.

In order to provide a seal between the outer side of the cam ring and the adjacent side wall of the chamber 16, sealing rods are utilized as at in the top of the chamber 16 and as at 81 in the bottom of the chamber. In order to hold the rods 80 in position and bias the rods and cam ring in one direction toward a central concentric position, an arched leaf spring 83 includes opposite ends resting on the sealing rods 80. In the bottom of the chamber a similar arched leaf spring 85 has opposite ends engaging sealing rods 81. Centrally of the arch, the leaf spring 83 is engaged by a spring-biased plunger 86 reciprocable in an adjustable threaded bushing 87 in the central housing member 10. The plunger 86 is biased by'a spring 88 seated against a cap 89 on the bushing 87. The plunger 86 has a reduced end portion 90 seated in a complementary aperture in the leaf spring 83. The leaf spring 85 biases the cam ring and sealing rods 81 in an opposite direction toward the neutral concentric position as a result of a springbiased plunger 92 similar to that described at 86.

In the absence of supply of fluid under pressure to either the top of the chamber 16 or the bottom of the chamber 16, both plungers 86 and 92 engage the cam ring 18, and the spring mechanisms illustrated are effective to maintain the cam ring in a central position concentric about the cylinder block to produce zero displacement. Fluid under pressure may be supplied to the top of the chamber 16 to move the cam ring to inflnitely vary displacement in one direction from neutral, ultimately to one extreme eccentric position as shown where the spring-biased plunger 92 functions as a stop. If fluid is exhausted from the upper part of chamber 16 and pressure is supplied to the lower part of the chamber 16, displacement may be varied in the opposite direction from neutral.

In operation, the hydraulic unit described herein may be utilized either as a pump or as a motor in various systems where pumps and motors are required. As an example, a pump of the type described herein is disclosed in my copending application Ser. No. 147,442 filed concurrently herewith as embodied in a system for supplying fluid to a transmission propulsion motor or the like and involving an automatic displacement control used in conjunction with such pump.

It will be understood that the provision of fluid chambers which are radially disposed and extend from the periphery of the cylinder block at one side of the axis, through the center of the cylinder block and near to the periphery of the cylinder block at the opposite side of the axis enables increased piston stroking relative to the diameter of the cylinder block. In the specific construction illustrated, the maximum stroke is almost equal to the radius of the cylinder block, a feature which cannot be provided in a construction with a plurality of radial pistons all in a single plane transverse to the cylinder block axis, because the cylinders would in tersect. The result is relatively large displacement per revolution with relatively small overall diametric dimensions. The over-center radial piston arrangement with relatively small cylinder block diameter facilitates rotation at high speeds. Another advantage of the overcenter radial pistons lies in the large camming angle between the piston and the cam ring for high torque efficiency when the unit is used as a motor. In particular, reference is made to the angle between the axis of the piston and the axis of the slipper, for example, at the two places where the slippers 67 appear in elevation at diametrically opposite positions in the cam ring 18 in FIG. 2. The main force of the piston and also the reaction are torque producing.

The over-center piston construction additionally facilitates axial porting near the periphery of the cylinder block at the opposite side of the cylinder block axis from the side where the piston projects, thereby enabling large flow capacity. The reduced cylinder block diameter enables relatively low surface speeds at the valve surfaces even at high rotational speeds. Adequate flow is further facilitated by porting each of the cylinders to both ends of the cylinder block through separate valve heads each of which communicates with a common inlet port and a common outlet port.

The provision of cam tracks with spherical surfaces in contact with mating spherical surfaces on the hearing slippers enables use of sealed pressure balancing chambers at the interengaged surfaces to reduce friction and wear. Location of the center of the cam surface offset from the center line of the piston provides a turning moment causing rotation of the slipper and piston to provide even wear on the ball joint and the piston.

The location of the cam ring in a sealed chamber enables remotely controlled automatic adjustment of the cam ring by means of fluid pressure. Application of fluid pressure directly to the cam ring enables precise control with relatively low fluid pressure.

I claim:

1. A rotary radial piston pump or motor device, comprising,

a. a housing,

b. a cylinder block rotatably mounted in the housing,

0. a plurality of radially disposed cylinders in the block extending from the periphery of the block inwardly past the axis of rotation of the block and arranged at axially spaced and angularly spaced positions in the block,

d. pistons slidable in the cylinders and urged outwardly on rotation of the block,

e. a cam ring surrounding the block eccentric thereto and having cam tracks for moving the pistons inwardly on rotation of the block,

f. an axial passage in the block intersecting each radial cylinder and extending the length of the block to opposite ends thereof for intake and discharge of fluid,

g. a valve member at each end of the cylinder block having an arcuate inlet port and an arcuate outlet port communicable successively with the axial passages as the block rotates, said inlet ports at opposite ends of the block being aligned with each other, and said outlet ports at opposite ends of the block being aligned with each other,

h. an inlet manifold extending longitudinally in the housing connecting the inlet ports at opposite ends of the block,

.an outlet manifold extending longitudinally in the housing connecting the outlet ports at opposite ends of the block,

j. an inlet in the housing communicating with the inlet manifold, and

k. an outlet in the housing communicating with the outlet manifold.

2. A device as defined in claim 1, wherein each cam track includes a spherical surface having a center on the axis of the cam ring displaced from the center line of the associated piston, and including a bearing slipper universally mounted on the end of each piston and having a spherical surface complementary to the cam track, a pressure balance chamber in the interengaged surfaces of the slipper and cam track, and passage means in the piston for conducting fluid under pressure to the pressure balance chamber.

A device as defined in claim 1 wherein each cam ing a spherical surface complementary to the associated cam track, means mounting the cam ring for adjustment to vary'displacement in a chamber having end walls in sealing engagement with the ring, means urging the ring toward a position concentric with the cylinder block, and means for applying fluid pressure to the periphery of the ring to move the latter toward a position of eccentricity.

4. A rotary radial piston pump or motor device, comprising,

a. a housing, b. a cylinder block rotatably mounted in the housing,

c. a plurality of radially disposed cylinders in the block extending from the periphery of the block inwardly past the axis of rotation of the block and arranged at axially spaced and angularly spaced positions in the block,

d. pistons slidable in the cylinders and urged outwardly on rotation of the block,

e. a cam ring surrounding the block eccentric thereto and having cam tracks for moving the pistons inwardly on rotation of the block,

. an axial passage in the block intersecting each radial cylinder and extending the length of the block to opposite ends thereof for intake and discharge of fluid,

g. a valve member at each end of the cylinder block having an arcuate inlet port and an arcuate outlet port communicable successively with the axial passages as the block rotates,

h. an inlet manifold in the housing connecting the inlet ports of the block,

i. an outlet manifold in the housing connecting the outlet ports,

j. means mounting the cam ring for adjustment radially of the cylinder. block to vary eccentricity in a chamber having end walls in sealing engagement with the ends of the cam ring and side walls in close engagement with the cam ring at opposite sides of prising,

a. a rotatable cylinder block,

b. a plurality of radially disposed cylinders in the cylinder block and arranged at axially spaced positions in the block,

c. pistons slidable in the cylinders and movable outwardly on rotation of the block,

d. a cam ring surrounding the block eccentric thereto and having cam tracks for moving the pistons inwardly on rotation of the block, each cam track having a cam surface spherical about a center on the axis of the cam ring axially displaced from the axis of the associated piston,

e. valve means for supplying fluid to and from the cylinders as the block rotates, and

f. a bearing slipper universally mounted on the end of each piston engaging the associated cam track and having a spherical surface complementary to the surface of the cam track so that the slipper is canted relative to the axis of the piston for rotation of the slipper and piston as the cylinder block rotates.

6. A device as defined in claim 5 including means defining a pressure balance chamber at the interengaged surfaces of each bearing slipper and its associated cam track, and passage means in each piston supplying fluid under pressure to the associated pressure balance chamber.

7. A device as defined in claim 5, including means mounting the cam ring for adjustment to vary displacement in a chamber having end walls in sealing engagement with the ring, means urging the ring toward a position concentric withthe cylinder block, and means for applying fluid pressure to the periphery of the ring to move the latter toward a position of eccentricity.

8. A rotary radial piston pump or motor device, comprising,

a. a rotatable cylinder block,

b. at least one radially disposed fluid cylinder in the cylinder block,

c. a piston slidable in the cylinder and movable outwardly on rotation of the block,

d. a cam ring surrounding the block eccentric thereto and having a cam track for moving the piston inwardly on rotation of the block including a cam surface spherical about a center on the axis of the cam ring axially displaced from the axis of the piston, x

e. a valve means for supplying fluid to and from the cylinder as the block rotates, and

f. a bearing slipper universally mounted on the end of each piston engaging the cam track and having a spherical surface complementary to the cam surface so that the slipper is canted relative to the piston to cause rotation of the slipper and piston as the cylinder block rotates.

9. A rotary radial piston pump or motor device, comprising,

a. a rotatable cylinder block,

b. a plurality of radially disposed cylinders in the cylinder block, I

c. pistons slidable in the'cylinders and movable outwardly on rotation of the block,

d. a cam ring surrounding the block eccentric thereto and having cam means for moving the pistons inwardly on rotation of the block,

e. valve means for supplying fluid to and from the cylinders as the block rotates,

f. means mounting the cam ring for radial adjustment relative to the cylinder block to vary eccentricity in a chamber having end walls in sealing engagement with the ends of the ring and side walls adjacent opposite sides of the ring at the periphery thereof,

g. sealing rods disposed between the cam ring and the side walls of the ring chamber,

h. means biasing the ring toward a position concentric with the cylinder block, and

i. means for supplying fluid under pressure to the ring and the sealing rods for moving the ring toward eccentric positions.

10. A device as defined in claim 9, including retainer means resiliently urging the sealing rods into sealing engagement between the cam ring and the chamber side walls.

11. A rotary radial piston pump or motor device,

comprising,

a. a housing,

b. a cylinder block rotatable in the housing,

c. a plurality of radial cylinders in the block extending inwardly from the periphery thereof and arranged at spaced positions in the block,

d. pistons slidable in the cylinders and movable outwardly on rotation of the block,

e. a cam ring surrounding the block eccentric thereto for moving the pistons inwardly on rotation of the block,

f. valve means for supplying fluid to and from the cylinders as the block rotates,

g. means mounting the cam ring for adjustment radially in opposite directions from a position concentric with the block including a ring chamber having end walls engaging opposite ends of the ring and side walls engaging the periphery of the ring at opposite sides thereof,

. sealing rods disposed between the cam ring and the side walls of the chamber at the top and bottom thereof and having opposite ends engaging end walls of the chamber,

i. means resiliently urging the cam ring and sealing rods to a position where the ring is concentric with the cylinder block, and

j. means for supplying fluid under pressure to the top and bottom of the chamber for moving the ring toward eccentricity in one direction or the other.

12. A device as defined in claim 11 wherein said resilient means includes an arched leaf spring in the top and bottom of the ring chamber each having opposite ends engaging the sealing rods to urge the ring toward concentricity.

13. A device as defined in claim 11 including an arched retainer member in the top and bottom of the ring chamber each having opposite ends engaging the sealing rods, and a spring-biased plunger in the housing engaging each arched member to urge the ring toward concentricity.

14. A device as defined in claim 13 wherein each arched member comprises a leaf spring.

15 A device as defined in claim 11 wherein the cylinder block includes a plurality of axially spaced cylinders with reciprocable pistons, and the cam ring includes a plurality of axially spaced cam tracks respectively associated with the pistons. 

1. A rotary radial piston pump or motor device, comprising, a. a housing, b. a cylinder block rotatably mounted in the housing, c. a plurality of radially diSposed cylinders in the block extending from the periphery of the block inwardly past the axis of rotation of the block and arranged at axially spaced and angularly spaced positions in the block, d. pistons slidable in the cylinders and urged outwardly on rotation of the block, e. a cam ring surrounding the block eccentric thereto and having cam tracks for moving the pistons inwardly on rotation of the block, f. an axial passage in the block intersecting each radial cylinder and extending the length of the block to opposite ends thereof for intake and discharge of fluid, g. a valve member at each end of the cylinder block having an arcuate inlet port and an arcuate outlet port communicable successively with the axial passages as the block rotates, said inlet ports at opposite ends of the block being aligned with each other, and said outlet ports at opposite ends of the block being aligned with each other, h. an inlet manifold extending longitudinally in the housing connecting the inlet ports at opposite ends of the block, i. an outlet manifold extending longitudinally in the housing connecting the outlet ports at opposite ends of the block, j. an inlet in the housing communicating with the inlet manifold, and k. an outlet in the housing communicating with the outlet manifold.
 2. A device as defined in claim 1, wherein each cam track includes a spherical surface having a center on the axis of the cam ring displaced from the center line of the associated piston, and including a bearing slipper universally mounted on the end of each piston and having a spherical surface complementary to the cam track, a pressure balance chamber in the interengaged surfaces of the slipper and cam track, and passage means in the piston for conducting fluid under pressure to the pressure balance chamber.
 3. A device as defined in claim 1 wherein each cam track is defined by a spherical surface having a center on the axis of the cam ring and displaced from the axis of the associated piston and including a bearing slipper universally mounted on the end of each piston and having a spherical surface complementary to the associated cam track, means mounting the cam ring for adjustment to vary displacement in a chamber having end walls in sealing engagement with the ring, means urging the ring toward a position concentric with the cylinder block, and means for applying fluid pressure to the periphery of the ring to move the latter toward a position of eccentricity.
 4. A rotary radial piston pump or motor device, comprising, a. a housing, b. a cylinder block rotatably mounted in the housing, c. a plurality of radially disposed cylinders in the block extending from the periphery of the block inwardly past the axis of rotation of the block and arranged at axially spaced and angularly spaced positions in the block, d. pistons slidable in the cylinders and urged outwardly on rotation of the block, e. a cam ring surrounding the block eccentric thereto and having cam tracks for moving the pistons inwardly on rotation of the block, f. an axial passage in the block intersecting each radial cylinder and extending the length of the block to opposite ends thereof for intake and discharge of fluid, g. a valve member at each end of the cylinder block having an arcuate inlet port and an arcuate outlet port communicable successively with the axial passages as the block rotates, h. an inlet manifold in the housing connecting the inlet ports of the block, i. an outlet manifold in the housing connecting the outlet ports, j. means mounting the cam ring for adjustment radially of the cylinder block to vary eccentricity in a chamber having end walls in sealing engagement with the ends of the cam ring and side walls in close engagement with the cam ring at opposite sides of the periphery thereof, k. means sealing the periphery of the ring adjacent the side walls of the chamber, and l. means for supplying fluid under pressure To the chamber to move the cam ring to a position eccentric to the cylinder block.
 5. A rotary radial piston pump or motor device, comprising, a. a rotatable cylinder block, b. a plurality of radially disposed cylinders in the cylinder block and arranged at axially spaced positions in the block, c. pistons slidable in the cylinders and movable outwardly on rotation of the block, d. a cam ring surrounding the block eccentric thereto and having cam tracks for moving the pistons inwardly on rotation of the block, each cam track having a cam surface spherical about a center on the axis of the cam ring axially displaced from the axis of the associated piston, e. valve means for supplying fluid to and from the cylinders as the block rotates, and f. a bearing slipper universally mounted on the end of each piston engaging the associated cam track and having a spherical surface complementary to the surface of the cam track so that the slipper is canted relative to the axis of the piston for rotation of the slipper and piston as the cylinder block rotates.
 6. A device as defined in claim 5 including means defining a pressure balance chamber at the interengaged surfaces of each bearing slipper and its associated cam track, and passage means in each piston supplying fluid under pressure to the associated pressure balance chamber.
 7. A device as defined in claim 5, including means mounting the cam ring for adjustment to vary displacement in a chamber having end walls in sealing engagement with the ring, means urging the ring toward a position concentric with the cylinder block, and means for applying fluid pressure to the periphery of the ring to move the latter toward a position of eccentricity.
 8. A rotary radial piston pump or motor device, comprising, a. a rotatable cylinder block, b. at least one radially disposed fluid cylinder in the cylinder block, c. a piston slidable in the cylinder and movable outwardly on rotation of the block, d. a cam ring surrounding the block eccentric thereto and having a cam track for moving the piston inwardly on rotation of the block including a cam surface spherical about a center on the axis of the cam ring axially displaced from the axis of the piston, e. a valve means for supplying fluid to and from the cylinder as the block rotates, and f. a bearing slipper universally mounted on the end of each piston engaging the cam track and having a spherical surface complementary to the cam surface so that the slipper is canted relative to the piston to cause rotation of the slipper and piston as the cylinder block rotates.
 9. A rotary radial piston pump or motor device, comprising, a. a rotatable cylinder block, b. a plurality of radially disposed cylinders in the cylinder block, c. pistons slidable in the cylinders and movable outwardly on rotation of the block, d. a cam ring surrounding the block eccentric thereto and having cam means for moving the pistons inwardly on rotation of the block, e. valve means for supplying fluid to and from the cylinders as the block rotates, f. means mounting the cam ring for radial adjustment relative to the cylinder block to vary eccentricity in a chamber having end walls in sealing engagement with the ends of the ring and side walls adjacent opposite sides of the ring at the periphery thereof, g. sealing rods disposed between the cam ring and the side walls of the ring chamber, h. means biasing the ring toward a position concentric with the cylinder block, and i. means for supplying fluid under pressure to the ring and the sealing rods for moving the ring toward eccentric positions.
 10. A device as defined in claim 9, including retainer means resiliently urging the sealing rods into sealing engagement between the cam ring and the chamber side walls.
 11. A rotary radial piston pump or motor device, comprising, a. a housing, b. a cylinder block rotatable in the housing, C. a plurality of radial cylinders in the block extending inwardly from the periphery thereof and arranged at spaced positions in the block, d. pistons slidable in the cylinders and movable outwardly on rotation of the block, e. a cam ring surrounding the block eccentric thereto for moving the pistons inwardly on rotation of the block, f. valve means for supplying fluid to and from the cylinders as the block rotates, g. means mounting the cam ring for adjustment radially in opposite directions from a position concentric with the block including a ring chamber having end walls engaging opposite ends of the ring and side walls engaging the periphery of the ring at opposite sides thereof, h. sealing rods disposed between the cam ring and the side walls of the chamber at the top and bottom thereof and having opposite ends engaging end walls of the chamber, i. means resiliently urging the cam ring and sealing rods to a position where the ring is concentric with the cylinder block, and j. means for supplying fluid under pressure to the top and bottom of the chamber for moving the ring toward eccentricity in one direction or the other.
 12. A device as defined in claim 11 wherein said resilient means includes an arched leaf spring in the top and bottom of the ring chamber each having opposite ends engaging the sealing rods to urge the ring toward concentricity.
 13. A device as defined in claim 11 including an arched retainer member in the top and bottom of the ring chamber each having opposite ends engaging the sealing rods, and a spring-biased plunger in the housing engaging each arched member to urge the ring toward concentricity.
 14. A device as defined in claim 13 wherein each arched member comprises a leaf spring.
 15. A device as defined in claim 11 wherein the cylinder block includes a plurality of axially spaced cylinders with reciprocable pistons, and the cam ring includes a plurality of axially spaced cam tracks respectively associated with the pistons. 